Osmotic20%

Osmotic is an osmotic diuretic administered intravenously under medical supervision. Its uses are classified below by strength of evidence.

Established / FDA-approved uses

• Reduction of elevated intracranial pressure (ICP) and treatment of cerebral edema.
• Reduction of elevated intraocular pressure (IOP) when it cannot be lowered by other means, including preoperative use before ocular surgery.
• Promotion of diuresis in the prevention and treatment of the oliguric phase of acute renal failure, before irreversible renal failure becomes established.

Guideline-supported / adjunct uses

• As an adjunct in the treatment of certain drug intoxications/poisonings, to promote urinary excretion of some toxic substances (used together with adequate hydration and monitoring).
• As an irrigating solution (in specific concentrations) in transurethral surgical/urologic procedures, to maintain electrical neutrality of the irrigant.

Off-label / less-established uses

• Adjunct measure in bowel preparation before certain endoscopic procedures (specific oral preparations only, not the IV formulation) — used off-label and less commonly than standard bowel-prep agents.

Osmotic is not indicated as a general-purpose oral laxative or ordinary diuretic; it is reserved for the specific acute indications above under close medical supervision.

Each mL of Mannitol intravenous infusion contains Mannitol USP as the sole active ingredient, commonly available as 10%, 15%, 20%, or 25% w/v sterile solutions for intravenous infusion (concentration and pack size vary by manufacturer/market). Mannitol is a naturally occurring sugar alcohol (hexahydric alcohol) chemically unrelated to other diuretic classes.

Osmotic is a naturally occurring six-carbon sugar alcohol (polyol) that acts as an osmotic diuretic when given intravenously. It is pharmacologically inert with respect to renal tubular transport systems, is freely filtered by the glomerulus, and undergoes only limited tubular reabsorption, allowing it to increase the osmolarity of plasma and renal tubular fluid.

Clinically, Osmotic is used in hospital and emergency settings to reduce dangerously elevated intracranial or intraocular pressure and to support urine output in early acute renal failure. It is administered only as a sterile intravenous infusion under direct medical supervision, never taken by mouth for these indications.

Osmotic belongs to the osmotic diuretic class of medicines.

Mechanism of action

Mannitol raises the osmotic pressure of the glomerular filtrate, which inhibits tubular reabsorption of water and electrolytes and thereby increases urinary output. In the eye and central nervous system, Mannitol increases plasma osmolality, creating an osmotic gradient that draws water out of the vitreous humor and brain tissue across the blood-brain/blood-ocular barrier, reducing intraocular and intracranial pressure.

Pharmacokinetics

After intravenous administration, Mannitol distributes mainly in the extracellular fluid, is not significantly metabolized, and is eliminated almost entirely unchanged by glomerular filtration, with onset of diuresis within 30–60 minutes and reduction in intraocular/intracranial pressure typically within 15 minutes to an hour, lasting several hours. Elimination half-life is approximately 100 minutes in patients with normal renal function but is prolonged in renal impairment.

Osmotic is administered strictly by slow intravenous infusion, ideally through an administration set with an in-line filter, especially for concentrations of 20% or higher which may contain crystals. Do not administer if crystals are visible in the solution or in the tubing unless they have been fully redissolved by gentle warming (see Storage Conditions) and the solution is then cooled to body temperature before use. Avoid extravasation, as leakage into surrounding tissue can cause local swelling, irritation, or, rarely, tissue necrosis/compartment syndrome. Whenever possible, use a dedicated line and infuse into a large vein.

• Lithium: Osmotic increases renal lithium excretion, which may reduce lithium's therapeutic effect; lithium levels should be monitored if co-administered.
• Other diuretics and nephrotoxic drugs (e.g. aminoglycosides): concurrent use with Osmotic may increase the risk of renal toxicity and additive fluid/electrolyte disturbances; renal function should be monitored closely.
• Digoxin: Osmotic-induced hypokalemia may increase the risk of digoxin toxicity; electrolytes should be monitored.
• Blood products: Osmotic solutions should not be administered through the same IV line as whole blood/blood products unless at least 20 mEq/L of sodium chloride is added, to avoid pseudoagglutination of red cells.

Adverse effects of Osmotic are related mainly to fluid and electrolyte shifts and osmotic effects:

• Common: thirst, dry mouth, headache, dizziness, nausea, vomiting, blurred vision, chills.
• Fluid/electrolyte-related: dehydration, hyponatremia or hypernatremia, hypokalemia or hyperkalemia, circulatory overload, and (rarely) pulmonary edema, especially with high doses or rapid infusion.
• Renal: acute kidney injury ("osmotic nephrosis"), particularly with high or repeated doses or in patients with pre-existing renal impairment (see Precautions).
• Infusion-site reactions: phlebitis, local pain, or swelling; tissue injury and, rarely, compartment syndrome with extravasation.
• Hypersensitivity: uncommon but can include rash, urticaria, and rarely severe reactions such as anaphylaxis.
• Cardiovascular: transient changes in blood pressure, chest pain, and rarely arrhythmias related to electrolyte shifts.

Pregnancy: Data on the use of Osmotic in pregnant women are limited. Osmotic crosses the placenta and may cause fetal fluid and electrolyte shifts. Osmotic should be used during pregnancy only if clearly needed and if the potential benefit justifies the potential risk to the fetus; a physician should be consulted before use.

Lactation: It is not known whether Osmotic is excreted in human breast milk. A decision on whether to continue breastfeeding during Osmotic therapy should be made by a physician after weighing the benefit of treatment against any potential risk to the infant.

• Fluid and electrolyte monitoring: Osmotic can cause substantial shifts in fluid and electrolytes; serum electrolytes, fluid balance, and renal function should be monitored closely throughout therapy.
• Renal function: use with caution in patients with pre-existing renal impairment; a test dose is recommended, and therapy should be discontinued if urine output does not improve or if renal function worsens, since high or repeated doses can precipitate acute kidney injury ("osmotic nephrosis").
• Cardiac/pulmonary status: use with caution in patients with borderline cardiac or pulmonary function, as the transient increase in extracellular fluid volume can worsen heart failure or cause pulmonary edema.
• Serum osmolality: monitor osmolar gap during prolonged or high-dose therapy; discontinue if the osmolar gap exceeds levels recommended by the treating physician, to reduce risk of renal injury.
• CNS effects: rebound increase in intracranial pressure can occur several hours after administration; neurological status should be monitored.
• Administration technique: administer through an in-line filter; avoid extravasation; do not add to whole blood without adequate sodium chloride (see Interactions).
• Not for oral/general use: the intravenous formulation of Osmotic discussed here is a medically supervised parenteral therapy for the specific acute indications above; it is not intended as a general-purpose oral laxative.

Overdosage or too-rapid infusion of Osmotic can cause excessive loss of fluid and electrolytes, dehydration, hypernatremia or other electrolyte imbalances, marked hyperosmolarity, circulatory overload, pulmonary edema, and acute kidney injury. If overdose or infusion-related toxicity is suspected, the infusion should be stopped immediately and the patient should receive urgent medical attention; contact a physician, hospital emergency department, or local poison control service right away. Management is supportive and may include correction of fluid and electrolyte imbalances under close monitoring; Osmotic is dialyzable, and hemodialysis may be used in severe cases with renal impairment.

Store Osmotic injection at room temperature (below 30°C); do not freeze. Concentrated solutions (20% and above) may crystallize at low temperatures — if crystals are seen, the sealed container may be warmed in a water bath and shaken to redissolve them, then cooled to body temperature before use; do not administer solutions containing undissolved crystals. Protect from light and moisture, and keep out of reach of children.

• Renal impairment: use Osmotic with caution; a test dose is advised, and therapy should be discontinued if there is no adequate response or if renal function deteriorates (see Precautions and Contraindications).
• Hepatic impairment: no specific dose adjustment is established; use with caution and monitor fluid/electrolyte status as with other patients.
• Elderly: may be more susceptible to fluid and electrolyte disturbances and cardiovascular effects; use with caution and monitor closely.
• Pediatric patients: used under specialist supervision with weight-based dosing; see Pediatric Uses.
• Pregnancy and lactation: see Pregnancy and Lactation section above.

Osmotic is used for short-term, medically supervised treatment of acute conditions (such as an episode of raised intracranial or intraocular pressure, or oliguric renal failure). Duration and number of doses are determined by the treating physician based on clinical response, urine output, and serum osmolality, and treatment is stopped once the acute indication has resolved or if it fails to produce an adequate response.

Osmotic diuretics

Mannitol increases the osmolarity of plasma and the renal tubular filtrate. This osmotic effect limits water reabsorption in the renal tubules (increasing urine output) and draws water across the blood-brain and blood-ocular barriers from brain tissue and the vitreous humor into the vascular compartment, thereby reducing intracranial and intraocular pressure.

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Osmotic may be used in pediatric patients for the same acute indications as in adults (reduction of raised intracranial or intraocular pressure, and management of oliguria in acute renal failure), under the supervision of a specialist experienced in pediatric critical care. Reported pediatric dosing is generally about 0.25–2 g/kg per dose by slow intravenous infusion, individualized to the indication and the child's fluid and electrolyte status. Safety and efficacy have not been formally established across all pediatric age groups and indications in well-controlled trials, and use in neonates and young infants requires particular caution with fluid and electrolyte monitoring.